Replace WiFi router transparently for clients?

Question

How to replace WiFi router or AP so that clients won't need to be reconfigure?

Is it enough to set same SSID (textual) and passwords? Or may be there are some invisible keys generated?

Answer 1

It is normally enough.

Clients recognizes AP by their beacon. The beacon that your new AP generates will be roughly the same as the older AP. The only striking difference will be the BSSID. But clients shouldn't fix the BSSID by default, otherwise, they would be unable to roam on large wireless networks.

On WPA/RSN-PSK, there are no permanent security associations between AP and clients. On RSN-Enterprise, there is only a temporary security association, which is used to speed up association.